Ebullition-type cooler



Patented Feb. 21,, 1939 UNITED STATES PATENT orricr.

The present invention relates to a cooler, for employment in a refrigeration plant.

One of the features of the present invention to the provision of a cooler in which the cooling agent is contained within a shell and the medium to be cooled is moved through a plurality of tubes which are positioned within the shell, and in which incoming refrigerating medium is introduced at the bottom and the flash gas formed therefrom in passing from the high pressure condition at the condenser to the low pressure condition at the cooler, is utilized for creating an within the shell.

Another feature of the present invention is the provision of a cooler having a shell and a plurality of tubes within the shell for the passage of the material to becooled, together with a distributing header tube located within the shell W for the delivery of the refrigerating medium along the length of the shell and having apertures therein for the distribution of refrigerant liquid and flash gas into the shell. With these and other features as objects in View, as will appear in the course of the following specification and claims, an illustrative form of practicing the invention is shown in the accompanying drawing in which:

Fig. 1 is a diagrammatic view showing theas- 30 semblage of the structure in a refrigerating plant. Fig. 2 is a transverse section, on a larger scale, substantially on line 2-2, through the cooler.

The cooler of the present invention is particucooler, by use of the. flash gas, this difficulty is eliminated.

0n the accompanying drawing, a refrigerating plant is illustrated as having a compressor C which compresses refrigerant gas and delivers it 60 as a hot compressed gas through a conduit Hlinto a condenser K, where it is cooled and liquefied and delivered into a receiver R from which it flows, usually as a hot refrigerant liquid, through av conduit H to the expansion valve EX. The

. 85 pressure drop occurring at passage through the active movement of the refrigerating medium' expansion valve leads to the formation of a quantity of gas which is known as flash gas, and in the cooling of the remaining liquid refrigerant through a low temperature. Hence, a mixture of liquid and gaseous refrigerant at low temperature and relatively low pressure passes through the conduit l2 into the cooler EV in which the heat exchange occurs so that the flash gas and other gas formed by evaporation is transferred by a conduit l3 back to the compressor C for recycling.

According to the present invention, the cooler EV is provided with a horizontal cylindrical jacket or shell l5 which is closed at its ends'by the head sheets I6 which are apertured to receive the tubes 11. Drums l8, is have flanges and are fixedly and tightly connected to the head sheets l6 and are themselves closed by end sheets to provide the inlet and outlet headers for the material to be cooled. Illustratively, relatively warm water may be admitted through an inlet pipe 2| .to the inlet header l8 so that it can flow through the tubes 11 to the outlet header l9 and be discharged through the outlet pipe Zia.

The conduit 12 passes through the shell l5 at a low point thereof, and is fixedly sealed thereto by welding or other suitable means. At the inner end of the conduit l2, 2. distributing pipe or header is in communication therewith, this pipe 25 extending horizontally in the illustrated form and closely adjacent the bottom of e shell l5 and having its ends closed in this illustrative form. The header 25 has a number of apertures 26 at its top and sides for the escape of flash gas therefrom. This flash gas is usually in an intimate mixture with the incoming refrigerant liquid, so that some of this liquid is carried through these apertures 26. Larger apertures 21 are provided at the bottom of the header 25 to permit excess liquid to move into the shell l5,

and thus assure the balancing of pressures between the interior of the header 25 and the interior of the shell l5, even though one or more of the orifices 26 may be blocked for any reason.

Likewise, it will be understood that the apertures The tubes I I are located for a major portion of the cross sectional area of the shell IE, but the upper portion of this space is left free of tubes neath the mouth of the conduit I 3, a baille .30 is extended chordally across the shell lS-and welded thereto. This baflle is illustrated as substantially horizontal and as located well above the upper row of tubes i1 and operates to prevent surging of liquid refrigerant into the gas return conduit l3. In the illustrated form, the tubes substantially fill the shell for the lower half of the cylinder, and for a distance above the horizontal axial plane equivalent to one-half the radius of the shell l5, while the baiiie 30 is located about half way between the top row of tubes I! and the top of the shell l5. Longitudinally of the shell I! (Fig. l), the baille extends for about onefifth of the length of the tubes l1.

In the particular illustrated form, the tubes I! are not uniformly distributed within the portion of the shell I! occupied thereby, although it is feasible to omit some tubes in a vertical line above the header 25.

In operation, the incoming refrigerant, comprising flash gas and refrigerant liquid, enters the distributing header 25 and fllls the same. The flash gas seeks immediate escape through the uppermost holes 26, and thus passes into the interior of the shell l and causes a rapid agitating or circulating movement of the liquid refrigerant. In case that there is little demand for cooling effect at the tubes ii, the valve EX is closed down and hence less flash gas is admitted, and thus a regulation of the agitation occurs with a regulation of the quantity of liquid refrigerant which is being admitted to the shell; while conversely a greater demand for refrigeration leads to the delivery-of a greater quantity of mixed refrigerant liquid and flash gas past the expansion valve EX into the header 2!. These effects are also produced according to the relative suction occurring at the conduit ii. If a greater quantity of gas is present in the header 25, the mixture is of course projected in greater volume, and a greater agitation occurs. A separation of flash gas from refrigerant, liquid also occurs in the distributing header 25; this flash gas passes to the top of the header 25 and escapes through the top scope of the appended claims.

depressed so that more flash gas may escape through lateral openings 26. Aslthedistributing header is horizontal in the illustrated form, this results in an advantageous proportioning of the flash gas along the length of the cooler, so that 5 adequate effects are produced at all points. Thus, the gas definitely escapes from the header 2!, and

a type of automatic regulation occurs thereat, along with the regulation efl'ected at the-expansion valve EX and by the operation of the expansion valve EX.

This invention is particularly advantageous with refrigerant media of the type of Freon; and with other refrigerating media whose character: istics (such as surface tension, viscosity, etc.) are, such that an active agitation is desirable.

It is obvious that the invention is not limited\ solely to the form of the construction shown, but that it may be modified in many ways within the I claim:

' 1. An evaporative cooler for a refrigerating plant having means for producing liquid refrigerant under pressure and an expansion device by which the pressure of the refrigerant is reduced 2 on its way to the cooler; said cooler comprising a receptacle for the liquid refrigerant, heat exchange devices located in said receptacle, a header located within and at the bottom of said receptacle and connected to the expansion device for receiving the refrigerant therefrom, said header being of such relatively large cross-sectional area as to permit a relatively slow travel of refrigerant therethrough and consequent effective separation of flash gas,from the liquid thereof, said header being perforated for the discharge of the flash gas and liquid to the space within the receptacle to agitate and circulate the liquid in the receptacle, and return means for gaseous refrigerant from said receptacle to the first mentioned means.

2. An evaporative cooler according to claim 1, wherein said header is an elongated tubular body disposed longitudinally of the receptacle, and said perforations are relatively large for passage of both liquid refrigerant and flash gas therethrough.

3. An evaporative cooler according to claim 1, wherein said header is tubular and of substantially the length of the receptacle, said perforations are spaced from the top of the header and relatively large for passage of both liquid refrigerant and flash gas therethrough, and a surgepreventing bailie is arranged within the receptacle adjacent said return means.

NORMAN H. GAY. 

